This paper analysed the floristic structure of the dominative plant species in principal plant communities. The author finded that Pinus tabulatformis and Picea crossifolia are the endemic distributive types in China and especially in the North China——Northwest,Quercus liaotungensis, Populus davidiana and Populus simohii are the endemic distrbutive types of China——Japan.Salix wallichiana and Ulmus pumila are the endmic distributive types of East Asia. Betula platyphylla is the endemic distribu...